ELI5 Pirates - why fly the skull and bones flag?

What was the point of the skull and bones pirate flag? why would you give away that you are a pirate? What does no quarter mean? What is the jolly roger? With pirates in literature like Blackbeard, Calico Jack, Long John Silver and Captain Jack, which pirates were historical and which were fictional?  .. we explain like I'm five Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion: hairweawekiller, stairway2evan, caesar_, pegajace, bulbliksmaz and tmahfan117 To the ELI5 community that has supported us so far, thanks for all your feedback and comments. Join us on Twitter: https://www.twitter.com/eli5ThePodcast/ or send us an e-mail: [email protected]